A height adjustment device of the generic type is known, for example, from DE 195 10 032 C2. In this device, a telescopic shock absorber, a helical support spring and a threaded drive with a control sleeve, a nut, and rolling elements inserted therebetween are combined into one unit. Here, the upper end of the support spring is located below the threaded drive, causing the unit to have a relatively large overall length.
The control sleeve of the height adjustment device described above is rotationally actuated by means of an external drive motor. However, the gear connection between the drive motor and the control sleeve is realized such that it has a high space requirement. Thus, the control sleeve has an exterior gearing on its upper face that meshes with a drive pinion of the electric motor. A rotationally secured guide sleeve, upon which the control sleeve is mounted in a rotatable fashion, is located radially inside the control sleeve.
The object of the invention is to provide a height adjustment device of the generic type that requires less installation space and that may be installed in a motor vehicle in a structurally favorable fashion and, optionally, may be retrofitted.